This calculator helps you compare the cost of a modular home (including site preparation and transport) with the cost of a traditional stick-built house. By entering a few key numbers, you can see total project cost and cost per square foot for each option, along with the difference between them.
The tool focuses on the main direct construction costs that most buyers can estimate from quotes or builder websites. It does not attempt to model every possible expense in a homebuilding project, which is why understanding the underlying formulas and assumptions is important.
The calculator uses straightforward arithmetic to turn your inputs into comparable numbers.
First, it combines the modular base price and the site-related costs to get a total modular project cost:
Where:
Then it divides this total by the modular home’s size to find cost per square foot:
Where:
For a traditional stick-built house, you enter the price per square foot and the size. The calculator multiplies these to get total cost:
Where:
The cost per square foot for the stick-built option is just P, the value you typed in.
Finally, the calculator looks at the differences between modular and stick-built costs:
Positive differences mean the modular home is cheaper; negative differences mean the stick-built option is cheaper for that metric.
When you run the calculator, you will typically see:
If the modular total cost is lower than the stick-built total cost, the calculator will show a positive savings figure. This means that for the combination of home sizes and prices you entered, modular construction requires less upfront spending.
If modular is also cheaper on a per-square-foot basis, it suggests that the modular package and site work are competitively priced relative to local stick-built labor and materials. In that case, modular may offer meaningful savings without necessarily sacrificing size or finishes.
If the stick-built total cost comes out lower, or the per-square-foot difference favors stick-built construction, it means either:
This does not automatically make modular a bad choice, but it indicates that the purely financial argument is weaker, and you may be paying extra for advantages like speed of construction or factory-controlled quality.
Note that your modular and stick-built homes can have different square footages. A smaller modular home might cost less in total but more per square foot, while a larger stick-built home might be more expensive overall but cheaper per square foot.
Use both metrics together:
To see how the formulas work in practice, consider the following scenario:
First, calculate the modular total cost:
M = B + S = $120,000 + $30,000 = $150,000
Then, calculate the modular cost per square foot:
Cm = M / Am = $150,000 / 1,500 sqft = $100 per sqft
Next, calculate the stick-built total cost:
T = P × As = $150 × 1,600 sqft = $240,000
The stick-built cost per square foot is simply the input price per sqft, $150 per sqft.
Now compare totals and per-square-foot values:
In this example, the modular home is smaller by 100 sqft, but it still delivers strong savings in both absolute dollars and cost per square foot. Even if site costs rose to $80,000, the modular total would be:
M = $120,000 + $80,000 = $200,000
At that point, total savings versus the $240,000 stick-built home would narrow to $40,000, and the modular cost per square foot would increase to:
Cm = $200,000 / 1,500 sqft ≈ $133 per sqft
This illustrates how sensitive the modular value proposition can be to site and transport costs.
The table below summarizes how the calculator compares the two approaches qualitatively. It is not a cost guarantee, but it can help you think about where each option tends to be stronger.
| Aspect | Modular home | Stick-built home |
|---|---|---|
| Cost structure in this calculator | Base factory price plus site prep & transport, divided by modular square footage. | Price per square foot multiplied by home size. |
| Typical cost predictability | Often more predictable due to factory-built components and fixed package pricing. | Can vary more with weather delays, labor availability, and on-site changes. |
| Construction timeline | Usually faster overall because modules are built off-site while site work happens. | Sequential process; more exposure to weather and schedule disruptions. |
| Design flexibility | Good within manufacturer’s catalog and engineering limits; fully custom layouts may be constrained. | High flexibility; easier to make unique or highly customized designs. |
| Site sensitivity | Costs can spike with difficult access, long transport distances, or crane challenges. | Also affected by difficult sites, but no need for large modules or specialized transport. |
| Perceived resale and appraisals | Can be comparable to stick-built in many markets, but appraisals may be harder where modular is rare. | Generally familiar to lenders and appraisers; comps may be easier to find. |
| Energy efficiency (typical) | Often strong due to factory quality control and tight construction tolerances. | Can be excellent with the right builder and materials, but more variability. |
To keep the calculator simple and fast, it makes several important assumptions. Keep these in mind when interpreting your results:
Your results are only as good as the numbers you enter. To make the comparison meaningful:
This tool is designed as a starting point for evaluating modular versus stick-built construction, not the final word. Some practical ways to use the results include:
Combine these numeric comparisons with qualitative factors like builder reputation, warranty coverage, customization needs, and local familiarity with modular projects.
Because the calculator focuses on direct construction costs, your actual all-in budget will usually be higher than the totals shown. Items like landscaping, driveways, appliances, furniture, and contingency funds for overruns should be added separately.
Before making a final decision, consider getting:
Used thoughtfully, this calculator can highlight the financial trade-offs between modular and stick-built homes and help you ask better questions as you plan your project.